The present invention is directed to underwater drilling and transportation of petroleum products from mobile submersible caissons which rest sequentially upon a platform placed on the sea bottom as various work functions are completed in turn by the various type caissons.
The cost of drilling oil wells from platforms at the sea surface increases as the depth of water becomes progressively deeper. Drilling now takes place at water depths in excess of one thousand feet and is progressing to twenty five hundred feet. The longer the drill string from the surface to the bottom the more materials which are consumed and the more time required prior to intiating the drilling activity. As a consequence, any method for reducing this delay and material expenditures has the effect of reducing the cost of the project.
The process of drilling from the surface in areas where seas are continually rough and often stormy, cold and in darkness for long periods of time is also very costly.
It is the object of the present invention to reduce well drilling time by submerging a mobile submersible caisson onto a platform placed on the sea bottom. The submerging process involves ballasting the caisson to lower the buoyancy until the remaining buoyancy can be overcome by the winch mechanism and the caisson slowly lowered down and sealed to the platform.
Another object of the present invention is to eliminate a moored platform and its cables, chains and anchors on and beneath the sea, thereby eliminating a costly obstruction at the site.
It is a further objective to provide the caisson with one atmosphere of air pressure, processed and recycled for the well-being and comfort of the crew and not subject to difficult weather conditions at the surface. Easy entry and exit to and from the caisson by means of a bell type work chamber or small submersible is provided.